In 1959 Moldex began
manufacturing the R50 Princess class locomotive using the original Rovex
tooling, that had been set aside in the early 1950’s. The tooling was repaired
and updated before shipping to Australia. The tools were shared with New Zealand
and the Moldex models were assembled from Australian made plastic mouldings,
motors and couplers, fitted to chassis sourced from the UK.

The model first appeared in
the 1959 Australian Catalogue and between then and the end of production in
1967, Moldex made seven known versions, not all of which appeared in the
catalogues and price lists. They were also used in six catalogued train sets and
at least one custom set over the same period.

The major visible
differences in the loco. body moulding between the Australian and UK versions of
the Princess, can be seen in the above illustration with the Australian model on
the top. The Australian model is missing the sandbox filler between the
steampipe and the lubricator, there is no builders plate on the front wheel
splasher, the nameplate is shorter and the topfeed cover is further forward on
the boiler. The original 8 spoke bogie wheel tool was also sent to Australia/NZ
and these were usually fitted, along with Australian made buffers, which were
heavier than the UK made ones. Aust. made locos. also had white painted
handrails, even on the black versions.

The Australian tender was
also made using the original Rovex tooling, modified to use the Mk3 coupler and
thus differed from the later UK version, as shown above. The underframe was in
two pieces with closed axleboxes and plain bearings, the tender sides were
higher with a different shape, there was no detail on the back and the body was
glued to the underframe, rather than screwed together. Aust. tenders were
usually fitted with the small disc wheels used in bogie wagons, or the slightly
larger ones used with the short TC passenger cars.